Why rapid COVID-19 tests are losing their ability to detect the virus
In short: While rapid antigen tests offer quick results in under an hour, their reliability is shifting. As new variants emerge and population immunity evolves, some tests are becoming significantly less sensitive, potentially providing a false sense of security that could inadvertently increase transmission risks.
The core tension in COVID-19 diagnostics lies in the trade-off between speed and sensitivity. Rapid antigen tests are highly valued because they can be performed on-site by doctors or individuals, often delivering results in an hour or less. However, these tests are inherently less sensitive than the gold-standard reverse transcription–polymerase chain reaction (RT-PCR) method. While antigen tests can identify transmissible infections, they frequently miss cases that an RT-PCR test would successfully detect.
Recent data highlights a concerning trend in diagnostic reliability. During a study conducted between November 2022 and May 2023, researchers found that among individuals infected with SARS-CoV-2, the sensitivity of rapid antigen tests was only 47% when compared to RT-PCR results. When compared to viral culture, the sensitivity was 80%. Even more striking, some commonly used rapid antigen tests have shown diagnostic sensitivities dropping below 30%, with sensitivity reaching near 0% during the first 48 hours of an infection.
This declining accuracy is a major concern for public health. As variants like Omicron emerge and population immunity changes, the effectiveness of widespread community-based testing remains unclear. Using insensitive tests might inadvertently raise infection rates by giving false confidence to those who are sick. Consequently, health experts suggest that those eligible for antiviral treatments should seek more sensitive diagnostic tests, such as RT-PCR, from healthcare providers to ensure they do not miss a diagnosis.
Opens the Intellect+ feed with this card first. Swipe up for the next one.
Sources
- Summary by Intellect · source: Why Don't We Have Better and Faster COVID-19 Tests? | SciShow News
- Also: Rapid antigen testing for COVID-19: Decreasing diagnostic reliability, potential detrimental effects and a lack of evidence to support continued public funding of community-based testing
- Also: SARS-CoV-2 Viral Shedding and Rapid Antigen...
- Also: www.nibib.nih.gov — Why rapid COVID tests aren't more accurate and how scientists hope to improve them
To cite this card, link to https://intellectplus.co.uk/app/science-why-don-t-we-have-better-and-faster-covid-19-tests-scishow-n.
How we source, check and correct cards: Editorial standards.
General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.
Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?
Related
More in Science · Latest · A–Z · All topics
